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Sweat, as stinky and uncomfortable as it can be, is a natural and healthy part of life, helping to cool the body. But excessive sweating can pose problems in your social life and relationships, and perhaps even to your emotional health.

How can you tell if you sweat excessively, beyond the body's normal needs? Check the answers below to find out.

When temperatures rise -- for any reason -- the sweat glands kick in to produce more sweat, Farris says. You might have a fever. You might be nervous. It may be hot outside. Or you may be exercising.

This is why "in summer, we sweat more," says Eric Schweiger, MD, a dermatologist and clinical instructor of dermatology at Mt. Sinai School of Medicine, New York.

Even your diet can play a role in your sweat output. "Some people have a sweating response to spicy foods," Schweiger says, as well as some hot foods or beverages.

Sweating: What's Normal, What's Not?

"The amount of sweat considered normal is quite variable and depends on the demands of the body," says Dee Anna Glaser, MD, a professor of dermatology at St. Louis University, in St. Louis, Mo., and president of the International Hyperhidrosis Society.

People may sweat less than a liter, or up to several liters a day, based on what they're doing.

"It is going to depend on whether you are an office worker in a climate-controlled building, or a roadside worker in Alabama," Glaser says.

If you're exercising or doing manual labor in a hot climate, expect to sweat a lot. It's normal.

What Is Excessive Sweating?

Excessive sweating, also called hyperhidrosis, means that you sweat far more than your body needs you to sweat. For example, if you sweat while sitting calmly at your desk, that is excessive sweating.

In hyperhidrosis, the body's cooling mechanism is so overactive that it produces four or five times the amount of sweat that you need. About 3% of the population has excessive sweating.

Because people have different "sweat needs," doctors say they can't put a solid number on the question: how much sweat does it take to be diagnosed with excessive sweating?

"It's very difficult to quantify, but most people really do understand when they are sweating too much," Glaser says.

''If you think you are sweating more than everyone else, or more than you used to, there is probably an issue going on," she tells WebMD.

Patients are very good at knowing how much is too much, Schweiger agrees. "Pretty much anyone who comes to me [complaining of] excess sweating has it," he says.

Except for women during the menopausal transition, there's no "normal" increase in sweating with age, Glaser says. If you think you're sweating more as you get older, don't just chalk it up to additional birthdays, she says.

One telltale clue that sweating may be abnormal, Glaser says, is sweating excessively from one area of your body only. (But sometimes excessive sweating occurs all over the body.)

Sweating without a need for it is another sign of abnormal sweating. "If you're sweating constantly in the winter in Chicago, that's probably excessive," Farris says.

Those with excessive sweating of the feet may produce so much sweat they are sliding out of their shoes, she says.

What Causes Excessive Sweating?

Most often, no cause of excessive sweating can be found. Doctors call it idiopathic -- meaning the cause is unknown or obscure. However, there may be genetic influences.

"About 50% of people with primary [excessive sweating] have a known family history," Glaser says.

This type of excessive sweating usually begins after puberty, Glaser says. Sweating just on the hands and feet often starts even younger, perhaps in infancy or during the toddler years.

A variety of other factors can cause excessive sweating, including underlying medical conditions and medicines, Glaser says.

For instance:

Frey's syndrome is a condition in which sweating occurs from just one side of the face when certain foods are eaten. It occurs after surgery on, or injury near, the saliva-producing glands.

Medications taken for endocrine problems, diabetes, and thyroid disease can also trigger excessive sweating.

So can certain high blood pressure medicines, as well as some antidepressant medications.

In addition, heavy sweating can be caused by infections, certain cancers, heart or lung disease, menopause, and sometimes even a stroke.

How Is Excessive Sweating Diagnosed?

It's important to keep in mind that most people who sweat heavily are normal, and not sick. If you are worried, and decide to see a doctor, most specialists will take a careful medical history, Glaser says.

Among the questions you can expect:

Do you sweat excessively from certain small areas of your body or all over?

When do you notice yourself sweating? Can you describe the situation?

What medications are you taking regularly?

Have you recently started taking new medications?

Have you had any surgeries recently?

Are you going through menopause?

Do you have family members who complain of excessive sweating?

If the doctor determines that your sweating is "idiopathic," and has no known cause, you can still treat the problem if you wish. Treatments range from simple home remedies such as showering more frequently to medications or surgery such as sweat gland removal.

It's important to see a doctor, Glaser says. So many of her patients, she says, have been told even by health care professionals: "It's no big deal."

But Glaser sees the impact excessive sweating can have on her patient's lives. "I have teenagers who will not raise their hands in class," she says, fearing their underarm area will be excessively and embarrassingly wet. "I have kids who have never gone on a date."

Quality of life is affected in older patients too. "It can affect business relationships," Schweiger says. "People are embarrassed to shake hands."

So don't sweat about the problem. Instead, talk to an expert. Remember, sweating is a good thing. But too much of a good thing can become a big problem.